Roller boom reefing and hoisting of a sail

ABSTRACT

Mechanism for hoisting and reefing a sail on a sailing vessel wherein the foot of the sail is connected along its length to a roller boom, and wherein the hoisting and reefing of the said sail is effected by halyard means passing over a pulley at an upper portion of a mast associated with the said roller boom and connected at one of its ends to a hoisting drum and connected at the other end to a reefing drum, and is also connected to the peak of the sail, and wherein the said reefing drum is connected to the said roller boom whereby the boom is rotatable with the said reefing drum, characterized in that there are provided: (a) rotatable clutch (25) means for selectively rotating the said hoisting drum (8) and the said reefing drum (4)(b) selective engaging and locking means (9, 9a, 26, 28) for selectively engaging the said clutch to the said hoisting drum or the said reefing drum, and automatically to lock the said hoisting drum with the said reefing drum at the end of a hoisting operation, and to unlock the said drums at the start of a reefing operation, and (c) brake means (12, 13) for providing a braking force on the hoisting drum during a reefing operation whereby free fall of the sail during reefing is prevented.

This invention relates to a mechanism for reefing and hoisting of a sailon a sailing vessel which is connected along its foot to a roller boomand wherein the rotation of hoisting and reefing drums by a halyardarrangement of the sails are controllable with respect to each other bya single crew member, the sail may be locked in any hoisted position andalso free fall of the said sail during a reefing operation is prevented.

The hoisting and reefing of a sail which is connected to anaxially-rotatable boom is a complicated maneuver to carry out. Thusconventionally the sail is hoisted by turning a winch around which ahoisting halyard connected to the peek of the sail is wound, and duringa reefing operation the winch is unwound and the rotatable boom rotatedby hand to roll the sail around it during its controlled fall, whichoperation requires at least two crew members to achieve the requiredresult.

An alternative arrangement is to provide a reefing drum connected to thesail roller boom, halyard means being arranged to pass over a pulley atan upper position of the mast and connected at one of its ends to thehoisting drum and at its other end to the reefing drum and alsoconnected to the peak of the sail. With such an arrangement it ishowever difficult to compensate for the build-up of halyard on the drumswhich thus require to be rotated at different relative speeds if thesail is not to be subjected to undue strain as it is rolled or unrolledfrom the roller boom. It is difficult to secure rapid locking of thesail in any particular position, the halyard normally being securedaround a clean which is time-consuming. Furthermore if the reefing drumis unconnected from the hoisting drum, it is difficult to prevent freefall of the sail during a reefing operation.

The present invention overcomes such difficulties in that the hoistingand reefing operations may be carried by a single crew member, ifdesired by remote control e.g. from a steering position, and whichfurthermore may be operated by one or more prime mover e.g. an electricor hydraulic motor

The invention provides a mechanism for hoisting and reefing a sail thefoot of which is connected along its length to a roller boom, andwherein the hoisting and reefing of said sail is effected by halyardmeans passing over a pulley at an upper portion of a mast associatedwith the said roller boom and connected at one of its ends to a hoistingdrum and connected at the other end to a reefing drum, and is alsoconnected to the peak of the sail, and wherein the said reefing drum isconnected to the said roller boom whereby the boom is rotatable with thesaid reefing drum, characterised in that there are provided

(a) rotatable clutch means for selectively rotating the said hoistingdrum and the said reefing drum

(b) selective engaging means for selectively engaging the said clutch tothe said hoisting drum or the said reefing drum, and to automaticallylock the said hoisting drum with the said reefing drum at the end of ahoisting operation, and to unlock the said drums at the start of areefing operation, and

(c) brake means for providing a braking force on the hoisting drumduring a reefing operation whereby free fall of the sail during reefingis prevented.

Preferably the clutch means comprises a clutch body portion connectableto the said reefing drum to rotate the said reefing drum in a reefingdirection and a clutch surface which engages the said hoisting drum whenthe clutch means is rotated in one direction to effect rotation of thesaid hoisting drum, and which disengages the hoisting drum when rotatedin the opposite direction while simultaneously the rotating clutch bodyportion is connected to the reefing drum to effect rotation of the saidreefing drum.

A particularly useful form of such clutch means consists of a ring gearforming the said clutch body portion, the geared periphery of which isdriveably connectable to the said reefing drum to rotate same in areefing direction only, and one side face of which is provided withdog-tooth elements engageable in corresponding slots in a facing surfaceof the said hoisting drum to form the said clutch surface.

Such a ring clutch, when provided with helical teeth on its periphery,forms part of a particularly effective embodiment of the said selectiveengaging and locking means, providing an automatic selective and lockingengaging means comprises a drivable helically-toothed gear which is inengagement with helically-toothed said ring gear which is axiallyslideably mounted whereby when the said ring gear is rotated in onedirection by the said helically-toothed gear causes engagement of thesaid clutch face by a throwing action caused by reaction forces betweenthe two sets of helical teeth, and rotation in the other directioncauses retraction of the said helically-toothed ring to its originalposition by opposite said forces causing disengagement of the saidclutch surface from the hoisting drum and simultaneous automaticengagement of the clutch body portion with the reefing drum.

Preferably the simultaneous automatic engagement of the clutch bodyportion with the the said reefing drum by the said clutch body portionis effected by ratchet means between the said clutch body portion and ashaft on which the said reefing drum is fixedly mounted.

Preferably the said brake means comprises a spring-loaded surfacebearing against a surface of the said hoisting drum whereby frictionforces acting between the two surfaces effects retarding of the hoistingdrum during a reefing operation.

The invention is hereinafter described in more detail in theaccompanying drawings, of which

FIG. 1 is a schematic elevational view of one embodiment of theinvention, and

FIG. 2 is an elevation partial cross-section of the hoisting and reefingmechanism of the arrangement of FIG. 1.

In the drawing, a hollow metal mast 1 of a sailing vessel is providedwith a roller boom 2 connected by a universal joint 3 a reefing drum 4fixedly mounted on one end of shaft 5 which is freely rotatably mountedthrough the said mast 1 in housing 6. The reefing drum 4 is providedwith a plate 7 at its end nearest the mast to protect the mast frombuild-up of halyard on the drum 4 during reefing operation.

On the other projecting end of the said shaft 5 there is freelyrotatably mounted a hoisting drum 8 on ball race 8a. A mainsail 10 isconnected at intervals along its foot (by means now shown) to the rollerboom 2. A halyard 11 passes internally of the mast passes over a pulley12 at the head of the mast 1, one end of the halyard being connected tothe reefing drum 4 so as to be windable therein the other end similarlybeing connected (after passing under further pulleys 13) to the hoistingdrum 8. The halyard is connected at an intermediate point along itslength to the peak 14 of the sail 10. If desired the halyard means maybe split so that the ends connect to spaced points on the luff of thesail.

Internally of the mast there is provided a motor 15 connected to a bevelgearbox through a gear box 17 and safety clutch 18 to a bevel gear 16.The bevel gear 16 meshes with a further bevel gear 19 which is itselfattached through shaft 21 to a vertically-disposed helical gear wheel 20rotatably mounted in casing 22.

A ratchet ring 23 is fixedly attached on the said rotatable shaft 5 andis mounted inside and co-axial with a second ring 24 which co-operatestherewith through a ratchet (26), whereby rotation of the said secondring 24 in one direction drives the shaft 5 (and also the reefing drum)and rotation of the ring 24 in the opposite direction disengages theshaft 5. The said second ring 24 contains a series of parallellongitudinal slots (28) on its external periphery engaging withcorresponding longitudinal teeth in a third ring 25 forming the clutchbody portion of clutch means mounted between the said helical gear 20 sothat the ring 25 forming the clutch body portion is axially slideablymounted on the said second ring 24. The side surface of the third ring25 facing the surface 10 of the hoisting drum is provided with lockingdog teeth 9 thus forming the clutch surface of the clutch means. Thewhole assembly of gears 20, 23 24 and 25 is contained in casing 11 whichhas a projecting portion extending into a circular recess of thehoisting drum 8 and containing a compression spring 13 bearing againstfriction pads 12 to form a friction brake when in contact with thefacing surface of the hoisting drum.

In operation the motor 15 is switched on to rotate in a direction toeffect hoisting of the sail 10 whereby the reaction forces operatingbetween the intercalating helical teeth on the gear 20 and ring 25 causethe ring 25 forming the clutch body portion to move to the right (as inthe drawing) by moving along the co-operating axial slots of the ring24, and the dog teeth 9 engage in corresponding slots 9a in the facingsurface of the hoisting drum 8, and at the same time the ratchetingaction between the second ring 24 and the first ring 23 causesdisengagement between the rings 23 and 24 thus disengaging the reefingdrum 4. By this means the sail 10 is hoisted to a required extent thereefing drum being unwound by upward movement of the halyard 11 whichhitherto was wound on the reefing drum. When the motor 15 is stoppedwhen the sail has been hoisted to the desired extent, the system becomeslocked against any movement which would cause lowering of the sail bythe action of the ratchet between the first and second rings 23 and 24respectively thus connecting and locking the hoisting and reefing drums.By this action, the tension in the halyards is preserved against anyflapping of the hoisted sail.

To lower the sail, the motor 3 is switched on to rotate in an oppositedirection. This causes the dog teeth on the ring 24 to become disengagedfrom the surface 10 of the hoisting drum, the ratchet between rings 24and 23 engaging ring 23 so as to effect rotation thereof, withcorresponding rotation of the shaft 5 and reefing drum 4. Thus thereefing drum rotates to pull the sail down and at the same time to rollthe sail over the rotating boom 2 which is connected to the reefing drumby universal joint 3. During this action the hoisting drum becomesdisengaged and is rotated by the pulling action of the halyard woundonto it.

During the reefing operation the friction braking action exerted by thespring 13 against the friction pad 12 and the facing surface of thehoisting drum causes a retarding action against sudden fall of the sail.

If desired, a manually-operated over-ride mechanism 27 may be providedto operate the system manually should power to the motor 15 fail.

The motor 15 may be an electric or hydraulically-operated prime mover.In the embodiment shown the motor is contained within the hollow mastfor protection against accidental knocking or the actions of waves. Ifdesired it may be enclosed in a casing external of the mast tofacilitate access.

While in the embodiment illustrated a single motor is used, if desiredtwo independently-operated motors may be used to provide the actuatingmeans, one driving the hoisting drum and the other driving the reefingdrum, the two motors, being interconnected so that the two drums aresimutanenously rotated in the appropriate directions, during hoistingand reefing operations. Alternative braking arrangements to the frictionbrake may be used and alternative clutch arrangements to the dog-toothengagement illustrated, may be used.

A particularly useful manner of carrying out the utilizing an existingroller boom on a sailing vessel is to provide an attachable unitcomprising a casing containing the mechanism hereinbefore described,connected to a hoisting drum motor and a power take-off wheel. The unitis then attached to the mast by suitable attachment means and a belt orchain is provided connecting the power take-off wheel to a roller boom,possibly through a reefing wheel, by a chain or rope to effect a reefingoperation.

Thus the present invention represents a substantial improvement overconventional roller reefing arrangements, providing a comprehensiveseries of operations operable by a single person, if required by remotecontrol of motor or motors used.

I claim:
 1. Mechanism for hoisting and reefing a sail on a sailingvessel wherein the foot of the sail is connected along its length to aroller boom, and wherein the hoisting and reefing of the said sail iseffected by halyard means passing over a pulley at an upper portion of amast associated with the said roller boom and connected at one of itsends to a hoisting drum and connected at the other end to a reefingdrum, and is also connected to the peak of the sail, and wherein thesaid reefing drum is connected to the said roller boom whereby the boomis rotatable with the said reefing drum, characterized in that there areprovided:(a) rotatable clutch means for selectively rotating the saidhoisting drum and the said reefing drum: said clutch means comprising aring gear forming a clutch body portion the geared periphery of which isdriveably connectable to the said reefing drum to rotate the saidreefing drum in a reefing direction only and a clutch surface formed onone side face of said ring gear which is provided with dog-toothelements engageable in corresponding slots in a facing surface of thesaid hoisting drum, which engages the said hoisting drum when the clutchmeans is rotated in one direction to effect rotation of the saidhoisting drum, and which disengages the hoisting drum when rotated inthe opposite direction while simultaneously the rotating clutch bodyportion is connected to the reefing drum to effect rotation of the saidreefing drum; (b) selective engaging and locking means for selectivelyengaging the said clutch to the said hoisting drum or the said reefingdrum, and automatically to lock the said hoisting drum with the saidreefing drum at the end of a hoisting operation, and to unlock the saiddrums at the start of a reefing operation: (c) brake means for providinga braking force on the hoisting drum during a reefing operation wherebyfree fall of the sail during reefing is prevented.
 2. Mechanismaccording to claim 1, wherein the said selective engaging and lockingmeans comprises a drivable helically-toothed gear which is in engagementwith helically-toothed said ring gear which is axially slideablymounted, whereby when the said ring gear is rotated in one direction bythe said helically-toothed gear causes engagement of the said clutchsurface thereof by a throwing action caused by reaction forces betweenthe two sets of helical teeth, and rotation in the other directioncauses retraction of the said helically-toothed ring to its originalposition by opposite said forces causing disengagement of the saidclutch face surface from the hoisting drum and simultaneous automaticengagement of the clutch body portion with the reefing drum. 3.Mechanism according to claim 2, wherein the said simultaneous automaticengagement of the clutch body portion with the said reefing drum iseffected by ratchet means between the said clutch body portion and ashaft on which the said reefing drum is fixedly mounted, the saidratchet means also acting to lock the said hoisting and reefing drums atthe end of a hoisting operation.
 4. Mechanism according to claim 1,wherein the said brake means comprises a spring-loaded surface bearingagainst a surface of the said hoisting drum whereby friction forcesacting between the two surfaces effects retarding of the hoisting drumduring a reefing operation.
 5. Mechanism according to claim 1 whereinthe said actuating means is driven by a motor.
 6. An attachable unitcomprising the mechanism according to any one of claims 1 or 2 to 5 forattachment to a sailing vessel provided with a roller boom, comprising acasing containing the said rotatable clutch means, selective engagingand locking means and said brake means, all in operative connection witha hoisting drum, motor and power take-off for a reefing operation on thesaid sailing vessel.
 7. Mechanism for hoisting and reefing a sail on asailing vessel wherein the foot of the sail is connected along itslength to a roller boom, and wherein the hoisting and reefing of thesaid sail is effected by a rope used as halyard passing over a pulley atthe upper part of a mast and connected at one of its ends to a hoistingdrum and the other end to a reefing drum with the luff of the sail beingconnected alongside the rope upwards to the reefing drum, wherein thesaid reefing drum is connected with the roller boom via a universaljoint whreby the boom is rotatable with the said reefing drum,characterized in that there are provided:(a) rotatable coupling meansfor selectively rotating the said hoisting drum and the said reefingdrum; (b) engaging and locking means for selectively engaging the saidcoupling to the said hoisting drum or the said reefing drum, andautomatically to lock the said hoisting drum with the said reefing drumat the end of a hoisting operation and to unlock the said drums at thestart of a reefing operation; and (c) brake means for providing abraking force on the hoisting drum during a reefing operation wherebythe winding of the sail around the reefing drum and the boom isimproved.
 8. Mechanism according to claim 7, wherein the said couplingmeans comprises a coupling body portion connectable to the said reefingdrum to rotate the said reefing drum in a reefing direction and acoupling surface which engages the said hoisting drum when the saidcoupling means is rotated in one direction to effect rotation of thesaid hoisting drum, and which completely disengages the hoisting drumwhen rotating in the opposite direction while simultaneously therotating coupling portion is effecting rotation to the said reefingdrum.
 9. Mechanism according to claim 8, wherein the said coupling meansconsists of a ring gear forming the said coupling body portion thegeared periphery of which is driveably connectable to the said reefingdrum to rotate same in a reefing direction only, and one side face ofwhich is provided with dog-tooth elements engageable in correspondingslots in a facing surface of the said hoisting drum, to form the saidcoupling surface.
 10. Mechanism according to claim 9, wherein the saidengaging and locking means comprises a drivable helically-toothed gearwhich is in engagement with helically-toothed said ring gear which isaxially slideably mounted, whereby when the said ring gear is rotated inone direction by said helically-toothed gear causes engagement of thesaid coupling surface thereof by a throwing action caused by reactionforces between the two sets of helical teeth, and rotation in the otherdirection causes retraction of the said helically-toothed ring to itsoriginal position by opposite said forces causing disengagement of thesaid coupling face surface from the hoisting drum and simultaneousautomatic engagement of the coupling body portion with the reefing drum.11. Mechanism according to claim 10, wherein the said simultaneousautomatic engagement of the coupling portion with the said reefing drumis effected by ratchet means between the said coupling body portion anda shaft on which the said reefing drum is fixedly mounted, the saidratchet means also acting at the end of the said hoisting and reefingdrums at the end of a hoisting operation.
 12. Mechanism according to theclaim 7, wherein sliding brake means effects retarding of the hoistingwinch drum during a reefing operation, to improve the winding of thesaid sail around the reefing winch drum and the boom.
 13. Mechanismaccording to claim 7, wherein the said actuating means is driven by aprime mover.